The present invention pertains to the aircraft monitoring and control art and, more particularly, to apparatus for determining the groundspeed rate of an aircraft.
A particular application of an aircraft system requiring groundspeed information is in a wind shear compensation system. Such a system is described in co-pending patent application Ser. No. 453,433, filed on Dec. 27, 1982, and having the same assignee as the present application. In such systems, windspeed is determined by measuring changes in the aircraft's relative groundspeed. Heretofore, expensive and complex systems have been employed to measure groundspeed changes accurately for use in wind shear compensation systems. Such prior art systems include inertial navigation systems, inertial reference systems, and others.
Prior attempts have been made at predicting groundspeed using inexpensive accelerometers and vertical gyros. These attempts have failed because instrument errors contaminate the resultant groundspeed output signals.
Inasmuch as the cost of installing highly sophisticated avionic systems in existing aircraft is prohibitive, and inasmuch as prior art attempts to monitor groundspeed by use of less expensive sensors have failed, there is a long felt need in this art for a groundspeed determining system which is accurate in operation but inexpensive to install and maintain.